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A traditional elevator installation (which includes a machine room) requires access inside the elevator shaft. Though I understand how someone might argue two. (g) Stop Switch in Pits. High-rise buildings pose additional concerns. Next, with multiple elevator banks, the controller will usually allow only one elevator at a time to operate, reducing the amount of emergency power required. If the equipment must remain energized to perform work, effective insulation and safe electrical working practices should be observed. In a time when increasing value is placed on even small amounts of real estate, elevator design must strive to configure, efficiently control and drive elements to whatever degree possible, and that is the thinking behind some alternate locations for these structures. It is important, where mandated, that there be no more than a single disconnecting means, so if emergency action is required, first responders will not be able to power down the equipment from one location. You are seeing this message for one of three reasons: You have reached your limit of free content. Car lighting, receptacles and ventilation 2. Flexible cords and cables (same conditions as within hoistways). As for height, the working space must extend from the grade, floor or platform to 6-1/2 ft. or the height of the equipment, whichever is greater. The elevator controller manufacturer must determine the required elevator controller SCCR as stated in the elevator controller specification and provide an elevator controller SCCR that is equal to or greater than the available fault current thats indicated in the design documents where there are multiple elevator controllers at different locations. (e) Pit Maintenance. Overcurrent devices protecting these branch circuits are to be located in the machine room or similar location. David Herres Examples of PPE that may be appropriate are non-conductive eye protection, clean leather or fire-resistant gloves, and natural-fiber or fire-resistant-rated long-sleeved shirts and pants, or fire-resistant-rated long-sleeved coveralls. All rights reserved. wide or the width of the equipment, whichever is greater. Loss of voltage to the control circuit for the disconnecting means shall cause a supervisory signal to be indicated at the control unit and required remote annunciation. NFPA 72 requires the control circuit between the Fire Alarm System and the shunt trip be monitored for integrity. All equipment in a machine room-less design is installed within the elevator shaft or exterior compartment near the elevator shaft, including the elevator controller and the elevator disconnecting means. Receptacle for pumps located in the pit shall be a single non-GFCI and shall be located 6 inches above the lowest landing. It employs specialists in Mobile, Alabama, and has technical and news correspondents around the world. From the website: Mohawk Lifts offers car lifts and auto lifts for purchase, including 2 post lifts, 4 post lifts, storage lifts, heavy duty mobile column lifts, parallelogram lifts, and other specialty items. The proposals resulted in adding new requirements in the 2017 NEC for: This article will also discuss other Code requirements that include selective coordination for elevators that are supplied by emergency, legally required standby or critical operation power systems or multiple elevators supplied from a single feeder, and shunt tripping of elevators where the elevator equipment room and/or shaft has a fire suppression sprinkler system. With these new NEC requirements, there is now the potential that an elevator controller SCCR may be required thats higher than what elevator manufacturers have historically furnished. (C) Duplex Receptacle. Home Articles Elevator World April 2012 Issue NEC Article 620: Elevators, Part I. PK ! Hoistway door interlock wiring from the riser must be flame retardant and have insulation suitable for a temperature not less than 200C (392F), much higher than that required for most raceway or cable applications. Auxilliary gutters are permitted in machine and control rooms between controllers, starters and similar apparatuses. Elevator Sump Requirements - Risi Stone Inc. Moreover, it is necessary to consider future worker safety for an indefinite period. GFCIs in elevator pits During an inspection of the elevators in a commercial building, the state inspector failed us for using a GFCI-type circuit breaker to protect a receptacle in the elevator pit. This may include wiring for signals, communication with the car, lighting, heating, air-conditioning and ventilation of the car or hoistway for fire-detecting systems and pit sump pumps. The light switch shall be located so to be accessible from pit access door. (To design and install an elevator for a Class I, Division 1 location would be quite an undertaking.). Flexible metal, liquid-tight flexible metal or liquid-tight flexible nonmetallic conduit 3/8 in. 4.0 (2 Reviews) (2) CLAIMED . The NEC rule specifies that the minimum size for paralleled conductors is 1/0 AWG, which is much too big for an elevator traveling cable. This is something that can be easily accomplished if the elevator controller manufacturer uses components in combination with overcurrent protective devices that are tested and listed with high combination SCCRs. Beginning with Article 320, Armored Cable (Type AC) and concluding with Article 398, Open Wiring on Insulators, each code-sanctioned cable and raceway is treated, ranging from the familiar Type NM (trade name Romex) to the exotic Integrated Gas Spacer Cable (Type IGS). 0 When you consider that an elevator is an enclosed room with one or more doors that people voluntarily enter so they may travel hundreds of feet up or down, several observations are in order. Luminaires must be lensed or equipped with wire guards to protect the lamps. For circuit breakers, time-current curves must be consulted as well as the circuit breaker manufacturers selective coordination tables. Many NEC articles address voltage limitations, and Article 620 is no exception. The traveling cable, moreover, may be run without raceway from inside the hoistway to elevator-controller enclosures and to the elevator car and machine room and similar locations outside the hoistway for a distance not exceeding 6 ft. -inch conduit is needed to the sump pump. Traditional wiring methods and materials come into play, as always, but it is necessary to rethink their deployment. +90 (216) 348 4876, India Office The proposals resulted in adding new requirements in the 2017 NEC for: Marking the elevator controller short-circuit current rating (SCCR) by the elevator control-ler manufacturer. Conductors supplying a single motor controller are to have an ampacity not less than the motor controller nameplate current rating plus all other connected loads. Please check your entries and try again. The vast majority of equipment serving the elevator is located within this room (i.e., elevator controller). When you're designing an electrical system for a building, don't let elevator requirements bring you down. Proper selective coordination in a multi-elevator installation on the same feeder ensures if one elevator develops a fault, the other units will not be shut down. However, space is frequently limited within the shaft and as such many ancillary components (shunt trip circuit breakers, fused disconnects) may need to be located outside of the elevator shaft. Required lighting shall not be connected to the load side of a ground-fault circuit interrupter. They must be in enclosures with doors or removable panels that can be locked in the closed position. The main concern is to ensure that workers may escape to safety in the awful circumstance of an arc-fault event. The pump sends hydraulic fluid from the reservoir to the cylinder, buried deep below the elevator shaft. Selective coordination is defined by the NEC as: Localization of an overcurrent condition to restrict outages to the circuit or equipment affected, accomplished by the selection and installation of overcurrent protective devices and their ratings or settings for the full range of available overcurrents, from overload to the maximum available fault current, and for the full range of overcurrent protective device opening times associated with those overcurrents.. Pit light with guard (ten foot candles min. Instruments: Use category III multimeters and be familiar with their use and limitations. The demand factors are given in Table 620.14, which allows significant reductions as the number of motors is increased. 2.2.2.6 . 974 0 obj <>/Filter/FlateDecode/ID[<64E135C225F1064D91BC8119D14516A9>]/Index[953 36]/Info 952 0 R/Length 105/Prev 204101/Root 954 0 R/Size 989/Type/XRef/W[1 3 1]>>stream For instance, one method to reduce the available fault current is to add an isolation transformer ahead of the elevator controller. +1-251-479-4514 | [emailprotected], Trkiye Office Cross-sectional areas of wireways are found by multiplying the two interior dimensions.) Accordingly, the supply wires are protected only for short circuit, and the overload protection is provided closer to the motor. Motor controllers are permitted outside the spaces specified above. Additionally, ampacities of the individual conductors and flame-retardant properties of the overall cable are important factors. It is worth noting that these NEC terms, used throughout Article 620, have been chosen to correlate with A17.1-2007 usage. (A) tells us that the lighting and receptacle (s) for the pit must be on separate circuits. Home Articles Elevator World June 2012 Issue NEC Article 620: Elevators, Part 2. N _rels/.rels ( j0@QN/c[ILj]aGzsFu]U ^[x 1xpf#I)Y*Di")c$qU~31jH[{=E~ It is stated that traveling cables are to be suspended at the car and hoistway ends, or counterweight end where applicable, so as to reduce the strain on the individual copper conductors to a minimum. Power for the elevator controller must first enter a lockable safety disconnect device, located adjacent to the door of the equipment room. Similarly, underground wiring in mines is not NEC regulated, although other, non-mine wiring below ground (such as lighting in an underground traffic tunnel) is covered. A few years later, in 1880, Werner von Siemens built the first electric elevator, setting the stage for a new industry that would change the world by making the practical use of tall buildings possible. We have circuited the receptacles and lights in the pits to the same circuit. For platform lifts and stairway chairlifts, the duty is intermittent. Three wiring categories within hoistways are allowed in addition, each with exceptions. Described below are several work practices that may be used to reduce arc-flash hazards when working on energized equipment: David Herres holds a New Hampshire Master Electricians license and has worked as an electrician in the northern part of that state for many years. The Uniform Building Code requires two-way communications between the central command center and the elevators, each elevator lobby, emergency power rooms, and by entries into enclosed stairways (Section 403.5.3). NEC Article 620 contains numerous other disconnect provisions, which must be carefully scrutinized prior to design work so the installation is compliant. ranged from 0.06 cal/cm2 to 0.95 cal/cm2, which indicates that the arc-flash hazard to employees is primarily to the hands and arms. Eazylift Albany LLC, 836 Troy Schenectady Rd, Latham, NY, Elevators It is of great importance that power to the various elevator functions can be quickly and reliably removed from the loads in case of emergency or for maintenance and troubleshooting. The elevator rails, like the ground system of the entire building electrical structure, are to be bonded to the lightning-system ground electrode so these all remain at the same potential even during a lightning event, ensuring side flash does not occur. Lights and convenience outlets in elevator pits shall be installed to comply with the requirements of CCR, Title 24, Part 3, Article 620. charlie b. Similar provisions are attached to elevator-car heating and air-conditioning disconnecting means, and to other utilization equipment. Where the elevator shaft and/or equipment room has a sprinkler fire suppression system installed, the elevator Code requires main line power to the elevator be removed prior to the application of water. Cross-sectional areas of conduits are given in Chapter 9, Table 4. As recommended in NFPA 70E, the National Elevator Industry, Inc. (NEII) commissioned an arc-flash hazard analysis (in compliance with IEEE Standard 1584-2002 for procedures for calculating the incident energy of the arc flash) by an independent consultant to determine at what level an arc-flash hazard exists to employees who work on energized elevator equipment. In such cases, it's economically justifiable to specify a traction type elevator. 3. This requirement applies to all controllers, disconnecting means and other electrical equipment that may need servicing, inspection or maintenance. Click to reveal Such design innovations require sophisticated wiring strategies. 354 Morgan Ave. Such cable groups are to be supported at intervals not over 3 ft. and located so as to be protected from physical damage. As greater numbers of elevators are added, the likelihood of them all operating simultaneously decreases so that it is permissible to reduce the feeder ampacity. Limit switches placed throughout the height of the shaft communicate with the controller and stop the cab at each landing. (ASME has a separate document, A18.1-2008 Safety Standard for Platform Lifts and Stairway Lifts). After reading this article, you should have learned: Which locations require sepa-rate, dedicated branch circuits Which branch circuits are not to be provided with ground fault circuit interrupter (GFCI) pro-tection Which locations must have one or more duplex receptacles Where overcurrent protection for hoistway, pit and machine-room lighting must be located How unsupported lengths of traveling cables are measured. ^W i word/document.xml=nr]6Id=,_$j9-"Y.iGU\h_}. By subscribing, you agree to our User Agreement and Privacy Policy & Cookie Statement. First, the ATS signals the elevators that it's about to switch over to emergency power preferably 30 sec or more prior to switching, which allows the elevator controller to bring each elevator cab to the nearest landing and stop, thus protecting the motors and electrical system. And so the needs can be very different. (Cross-sectional areas of conductors are given in Chapter 9, Tables 5 through 8.